Refrigeration method and apparatus



Ju xly 25, 1944. R. T. IIBRIZZOLARA I 2,354,496

REFRIGERATION METHOD AND APPARATUS Filed May 14 1943 I Patented July 1944 Robert T. Briuolara, New Dorp,

. Staten Island, N. Y.

Application May 14, 1943, Serial No. 486,991

- 8 Claims.

This invention relates to refrigeration and relates more particularly to refrigeration systems in which volatile refrigerants are circulated between evaporators and condensers through the extraction of heat from the condensers by indirect contact with low temperature mediums.

In one embodiment of this invention an inclined flat walled plate condenser is placed in the lower portion of an insulated cabinet. A cold substance such'as water ice or dry ice is placed upon the condenser forliquifying refrigerant vapor received from an evaporator exposed to a heat load. Liquid from the condenser drains by gravity into a receiver. The evaporator is located above the condenser and the refrigerant is lifted from the receiver to the evaporator by refrigerant vapor flowing through lift fittings.

A feature of this invention resides in controland serves to supply refrigerant fitting It.

The tube l'l connects the lift fitting l6 with the upper lift fitting l8 and the tube It connects the into the lift lift fitting It with the separator 20. The sepa-' rator 20 is connected by the tube 2| to the evaporator 22. The evaporator 23 is connected to the evaporator 22 by the tube 24.

The suction tube 25 connects the upper portion of the. evaporator 22 with the condenser and serves to return vapor thereto to be condensed therein. The tube 26 connects the upper portion of the evaporator 23 with the upper portion of the lower lift fitting l6 and supplies vapor thereto for lifting the liquid refrigerant to the upper lift fitting l8 as will be described.

The evaporators 22 and 23 illustrated are thin rectangular plate type evaporators'with metal ling the refrigerating effect by flooding back liquid 4 from the receiver into the' condenser when it is I desired to reduce or discontinue the .refrigeratlon.

Another feature of this invention resides in supplying refrigerant vapor to the lift fittings from an evaporator located at a higher level.

Objects of the invention are to simplify and to improve the performance of refrigeration systems.

The invention will now be described with-reference to the drawing' which is a diagrammatic view with some of the components in section, of a refrigeration system embodying this invention.

The condenser 5 has thin metal walls, the upper and lower walls being parallel and relatively closely spaced and being inclined from the horizontal to permit drainage of liquid from the condenser. The condenser has the enlarged lower portion 6 which serves as an accumulator well.

The condenser'is located within the insulated Y ice bunker 1 which contains dry or water ice 8 which rests upon theupper wall of the condenser and serves to extract heat from the refrigerant.

therein so as to liquify same.

The receiver 9 is located below the condenser 'andn isconnected with the accumulator well by the drain tube It through which the refrigerant liquid-flows from the condenser into the receiver.

The tube It terminates in the lower portion of mostat l3 as will be-described.

The drain tube III has a T-fltting it between.

the condenser and the receiver and the tube l5 is connected into this and 'into' the lift fitting, I.

walls such as are commonly used for chilling a space in which substances to be kept 0001' are stored. They could be tubes for air cooling purposes where it.is desired tochill the air in air conditioning systems.

The system is charged as usual with a refrigerant of any well known type such, for example, a Freon," methyl chloride or ammonia. Since the temperature of the ice used for cooling the condenser, is the lowest temperature in the system, it will establish a condensing temperature which results in a corresponding pressure being established throughout the system, which pressure depends upon the characteristics of the refrigerant used, upon the temperature of the ice used and the extent of surface contact.

- contained therein. 40'

that the lower or drainage end of the condenser This is true however, only when the condenser -serves truly as such and is drained of liquid. If

.the condenser fills with liquid, it ceases to con- M dense vapor and serves only to pr'ecool the liquid 7 When this condition exists the pressure within the system depends only upon the temperature of the evaporators and upon the ambient temperature of the space to which they are exposed.

The condenser 5 is sloped as illustrated to aid in drainage and the drainage level may be so set acts as a refrigerant liquid precoqler.

- The liquid upon condensing drains into the receiver i 'and is carried through the tube i5 into the hi I fitting it where a liquid level is estab-- lished t the same height as is in the condenser (shown as hh on the drawing) f The liquid draining into the receiver Q is con-.-

ducted to the bottom. Thisreceiver which-is a refrigerant to equal the total contents of the condenser, the lift. fitting, and the interconnecting piping. It may be small since its capacity need ing through the tube I I into the accumulator well i where it is cooled and other liquid replaces it.

If the heat reaching the receiver 9 is excessive or the accumulator 'well 6 is devoid of liquid, some vapor will form-in the receiver and will pass into The lift fittings, I. and II are small cylinders I which use refrigerant vapor to lift the refrigersure must be greater than the terminal pressure on the .tube I9, the separator 20 and the evaporator 22 but not greater than that of the liquid column M. which column serves as a seal against the vapor blowing back into the condenser. This por escape through the tube II being checked by the'valve I2, builds up and floods liquid back through the tube ll into the condenser and into the lift fitting I. In flooding back into the lift fitting it reduces its pumping capacity by deepening the liquid seal. Due to the flooding of the condenser, it ceases to be a condenser and evaporation in the evaporators 22 and 23 ceases. The

The ice and the condenser in the system de- .opens through the influence of bulb l3. this occurrence the vapor trapped in the receiver It merely becomes subcooled liquid at thev system pressure established by the evaporators.

Complete flooding of the condenser discontinues evaporation. Partial flooding reduces the ing means partial or complete'i'iooding.

In due course, through the refrigerated space rising in temperature, the thermostatic valve I2 With 8 is released through the tube I I and liquid in the condenser drains intoit to fill it and in so the condenserto recondense. It is intended that is doing exposes the condenser surface again to the receiver shall be of such size andv have such serve as a condenser and as a means for drop- I exposure that the amount of precooling in the pins the evaporator pressures and thus reestabv drainage portion of the condenser be dissipated lish the evaporation cycle for cooling. The conby the exposure of the receiver to the air in a trol described in the foregoing does notinvolve.

- space having a warmer ambient temperature. 2o disturbing the volume of the liquid in the evaporator.

scribed in the foregoing correspond to the compressor.in-a mechanical system. In a mechanical system, the capacity of the compressor is the limitation on how low a pressure the evaporator can be pulled down to and thereby its temperature. But in the ice system described herein any desired low pressure can be attained by increaspressure is obtained through the tube 2' from 30 ing the size of the condenser which can melt and the evaporator 28 and is the pressure of the evap absorb heat from the ice at any rate impressed orated refrigerant. The vapor depresses the liq upon it. l v uid in the fitting II and blows through the tube While this "invention-has been described in con- II forming bubbles and lifting the liquid. This nection with theuse of ice-or other stored source column of rising bubbles and entrginedliquid 35 of cold for absorbing heat from a condenser, it terminates in the separator 2|! and th .-liquid is to be understood that certain features are not and vapor separate therein. limited to use in such a system but may be used The liquid in the evaporator 22 evaporates in in amechanical systemdue course since its temperature and pressure re- While one embodiment of the invention has lations are. such that it absorbs heat from the -10 been described for the purpose of illustration, i space it serves. Liquid from the evaporator passes should be understood. that the invention. is not through the tube 24 into the evaporator 23. The limited t the a t apparatus and a rans m nt liquid in the evaporator establishes itself to have f app at s ust a d s modifications there f a height which is less than that of the liquid may suggest. themselves to those skilled in the in the evaporator 22 by the amount h. This dif-- art without departure C({Olll the essence of the ference in height is-caused by the resistance lnv nti nthrough the lift. operation previously described. W i claimed is! The evaporated vapor in the evaporator a ust 1. A refrigeration system including an evapovercome this resistance. Since the ;vapor, r so orator, a condenser, and a liquid receiver consure in the evaporator 21 i l in in t nected in a refrigerant circuit, said receiver beevaporator 23,.the liquid levelin theevaporator ins located below said condenser, a tube for 23 must be lower. The differential pressure cordraining liq from i condenser into said responding to n is such as to blow through the e r. a te tube for co ducting vapor from lift resistance and into th c d n r, said receiver back to said condenser, and means The process of evaporatiqn having reduced t for throttling said separate tube for causing liqambient temperature to that d t evap.. vuidfrom said receiver to flood back throughsaid r ing cycle must be stopped to h k further I firstmentioned tube into said condenser whens cooling. This is accomplished accordlngto this desired condition is b l about by the invention by control of the :valve l2 by the theromtion of refrigerant in said'evappmtmfl mostatmbulb which mai placedv m mntact 00 2. A refrigeration system including an evapwith the evaporator or in the space beingrefrignaemen i liquid receiver erated. When the thermostat closes the valve, meted a refrigerant clruit-ssid receiver the liquid in the receiver continues to absorb r W tube heat, to warm up and theneto vaporize. The va- I 8 liquid from and ed said s ceiver, a separate tube for conducting vapor from said receiver back to said condenser, and means including meansresponsive to a condition brought aboutzby the evaporation of refrigerant in said evaporator for throttling said separate tube for causing liquid from said receiver to'fiood back. through said first mentioned tube into said condenser. r j

3. The method of controlling a refrigeration ""iiquidin -thecondenser precools. but does not essystem including a. condenser, a receiver and an tablish a pressure relationship for the system.

70 evaporator, which comprises. using vapor from said receiver for flooding back liquid from said receiver into said condenser for reducing the draining liquid from said condenser into said r'eceiver, a separate tube for conducting vapor from said receiver back to said condenser, means for throttling said separate tube for causing liquid from saldreceiver to flood back through'said first mentioned tube into said condenser when a desired condition is brought about by the evaporation of refrigerantin said evaporator, and means including means utilizing refrigerant vapor for lifting liquid from said receiver to said evaporator.

6. A refrigeration system including an evaporator, a condenser, and a liquid receiver connected in a refrigerant circuit, said receiver being located below said condenser, a tube fordraining liquid from said condenser into said receiver, a separate tube for conducting vapor from said receiver back to said condenser, means including means responsive to a condition brought about by the evaporation of refrigerant in said evaporator for throttling said separate tube for causing liquid from said receiver to flo'od back through said first mentioned tube into said condenser, and means including means utilizing refrigerant vapor for lifting liquid from said receiver to said evaporator.

7. A refrigeration system including an evaporator, a condenser, and a liquid receiver connected in a refrigerant circuit, said receiver being located below said condenser, means for draining liquid from said condenser into said receiver, said condenser being inclined at an oblique angle to the horizontal whereby drainage rof liquid therefrom into said receiver is facilitated, means for flooding liquid back from said receiver into said condenser, and means responsive to a condition brought about by the evapv oration of liquid in said evaporator for controlling said flooding and draining means.

8. A refrigeration system including an evaporator, a condenser, and a liquid receiver connected in a refrigerant-circuit, saidreceiver be- 2 ing located below said condenser, said condenser being inclined at an oblique angle to the horizon tal and having a liquid precooler formed at the lower. end thereof, means for draining liquid from said precooler into said receivenand means including means responsive to a condition brought, about by the evaporation of liquid in said evaporator for flooding baci: liquid from said receiver into said precooler.

' ROBERT T. BRIZZOIARA. 

